Intracranial hemorrhage after ventriculostomy
Intracranial hemorrhage is a recognized ventriculostomy complication from cortical vessel damage
Epidemiology
Based on a metaanalysis, the overall hemorrhagic complication rate from ventriculostomy placement by neurosurgeons is approximately 7%. The rate of significant hemorrhage from ventriculostomy placement is approximately 0.8%. Further prospective studies are warranted to better address this question 1).
Risk factors
Advanced age is predictive of EVD-related hemorrhage in patients with intracerebral hemorrhage (ICH) 2).
Preoperative anti-platelet medication appears to affect EVD-related hemorrhage development 3).
Also, evaluating the risk of hemorrhage before the antiplatelet treatment reaches its full effect may lead to false results. Studies with small patient groups with antiagregant therapy and impaired thrombocyte functions also contribute to the literature. Larger studies regarding this subject are needed 4).
The use of antiplatelet or anticoagulants has previously been shown to increase hemorrhagic complications of ventricular catheterization. Although heparin use 24 h after ventriculostomy appears safe, the safety of heparin immediately (within 4 h) after ventriculostomy is unknown. The objective of this study was to assess the safety of heparin immediately (within 4 h) after ventriculostomy in subarachnoid hemorrhage (SAH) patients undergoing endovascular treatment.
Although heparin appears to be safe after 4 h, immediate heparinization (within 4 h) after ventriculostomy significantly increases the odds of tract hemorrhage. Additional time should be afforded between ventriculostomy and heparinization to avoid potentially devastating external ventricular drain tract hemorrhage. It is advisable to wait a sufficient time (at least 4 h) after ventriculostomy before embarking on endovascular treatment of ruptured aneurysms 5).
The cortical bridging venous segment protruding into the inner skull depression (CBVISD), a distinctive structure found in the calvarial convexity, may be a potential risk factor for hemorrhagic complications.
The anteroposterior axis was delimited anteriorly by the supraorbital bar and posteriorly by the coronal suture, which was further divided into four parts: the forehead (FH), anterior frontal (AF), FH-AF junctional, and posterior frontal (PF) regions.
The CBVISDs are most frequently located at the common trephination site of external ventriculostomy. Trephination performed in the FH and FH-AF junctional regions may be safer than that in more posterior frontal areas 6).
A study evaluates the impact of periprocedural risk factors on rates of external ventricular drain (EVD)-associated hemorrhage in the setting of endovascular treatment of intracranial aneurysms.
The results demonstrated no significant risk factor related to EVD-associated hemorrhage rates, and support the safety of EVD placement in the peri-endovascular treatment period 7).
Outcome
It appears to be of minor clinical significance in the majority of patients 8).
Prevention
In a report, Robertson et al. from the Department of Neurological Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts assessed hemorrhagic risk by simulating traditional ventriculostomy trajectories and using CT angiography (CTA) with CT venography (CTV) data to identify potential complications, specifically from cortical draining veins.
Radiographic analysis was completed on 50 consecutive dynamic CTA/CTV studies obtained at a tertiary-care academic neurosurgery department. Image sections were 0.5 mm thick, and analysis was performed on a venous phase that demonstrated high-quality opacification of the cortical veins and sagittal sinus. Virtual ventriculostomy trajectories were determined for right and left sides using medical diagnostic imaging software. Entry points were measured along the skull surface, 10 cm posteriorly from the nasion, and 3 cm laterally for both left and right sides. Cannulation was simulated perpendicular to the skull surface. Distances between the software-traced cortical vessels and the virtual catheter were measured. To approximate vessel injury by twist drill and ventricular catheter placement, veins within a 3-mm radius were considered a hemorrhage risk.
In 100 virtual lines through Kocher's point toward the ipsilateral ventricle, 19% were predicted to cause cortical vein injury and suspected hemorrhage (radius ≤ 3 mm). Little difference existed between cerebral hemispheres (right 18%, left 20%). The average (± SD) distance from the trajectory line and a cortical vein was 7.23 ± 4.52 mm. In all 19 images that predicted vessel injury, a site of entry for an avascular zone near Kocher's point could be achieved by moving the trajectory less than 1.0 cm laterally and less than 1.0 cm along the anterior/posterior axis, suggesting that empirical measures are suboptimal, and that patient-specific coordinates based on preprocedural CTA/CVA imaging may optimize ventriculostomy in the future.
In this institutional radiographic imaging analysis, traditional methods of ventriculostomy site selection predicted significant rates of cortical vein injury, matching described rates in the literature. CTA/CTV imaging potentiates identification of patient-specific cannulation sites and custom trajectories that avoid cortical vessels, which may lessen the risk of intracranial hemorrhage during ventriculostomy placement. Further development of this software is underway to facilitate stereotactic ventriculostomy and improve outcomes 9).